JPS5932279B2 - Operating device with weight compensation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to an operating device having an arm with a gripper or the like at its free end, the arm having first and second links, one connecting link and one connecting link. The arm is arranged in a four-bar chain link system consisting of web links and supported by a pivotable weight compensation system, in which case the arms are arranged at one end of each of the first and second two links of the four-bar chain link system. The hinges are connected via hinges, and the hinges and the arm portion between the hinges form a connecting link of a four-bar chain link system, and the other end of the first link is connected to the bracket of the operating device. The other end of the second link is connected via a hinge to a web link that is pivotable about the fixed support with respect to the bracket. D. The above link is operatively connected to a weight compensation system.

An operating device of the above type proposed by DE 27 01 151 A1 is used, for example, in assembly, welding, boring, material handling, transport, enameling and glazing operations, etc. The general working form of operating devices containing grippers is such that, on the one hand, a four-bar chain link system allows the gripper as a whole to move along three coordinate axes, and on the other hand, the gripper itself also performs a movement along three coordinate axes. It is something. The three coordinate axes of motion by the four-bar chain link system are called the fundamental axes in this case, and the three coordinate axes of motion of the gripper are called the hand axes. According to these movements, a workpiece or tool can be moved from a certain point to an arbitrary location and placed in an arbitrary posture (position state). Known operating devices (e.g. French Patent No. 2)
348020), one axis of the hand is moved via one link of a parallelogram, and a large amount of power is required for the movement of one axis of the hand.In this case, the rotation range of the three coordinate axes is Depending on the particular configuration, different forces from self-weight and loading arise, and these forces are supported by the constant development of a counter force.

According to a proposal from DE 27 01 151 A4, instead of parallelogram links, a four-bar chain with links of different lengths and thus with different link angles at the hinge point is used. This requires significantly less power.

This irregular four-bar chain support, however, resulted in incomplete weight compensation. This weight compensation can take place, for example, in the case of a piston loaded with a pressure medium, which produces a larger or smaller counterweight depending on the extent of its outward or inward pivoting of the four-bar link system. . This piston does not move when the gripper moves in and out in the horizontal direction. Therefore, if the location of the load changes, no change in supporting force occurs. The force exerted on the piston changes only during the raising and lowering of the gripper, also due to the compression or expansion of the pressure medium applied to the piston. The object of the invention is to improve the weight compensation system so that it is adapted to any localization of the load location, so that the load moment and the support moment are compensated relative to each other regardless of the change in gripper location. The goal is to According to the invention, this problem is solved in an operating device of the type mentioned at the outset, in which the weight compensation system has a pivotably supported support lever, on which two coupling levers are connected. are connected via a common hinge, and the other end of the first connection lever is connected to the hinge to which the second link is connected to the web link. the second link is supported, and the second connection lever is connected to a hinge on the first link, and the hinge is connected to the web link and the second link. This is achieved by arranging the bearing, which is immovable with respect to the bracket, away from the hinge towards the side connecting the bracket.

According to the invention, it is possible to provide a weight compensation system that adapts to changing forces.

The invention will now be explained with reference to the illustrated embodiment.

The operating device shown in FIG. 1, which is constructed as a four-bar chain link system, has an arm 1 on which grippers 2 are attached which are movable in different directions.
The four-bar chain link system itself consists of two long first and second links 3, 4 of different lengths, one connecting link 5 as an intermediary link, and one web link 6 as a so-called web. The connecting link 5 is a component of the arm 1. The web link 6 and one of the first links 3 are rotatably supported on a bearing c which is immovable relative to the bracket 7. The other hinge d of the web link 6 is connected in the usual manner in a height-adjustable manner to a drive, not shown. The four hinge points of the four-bar chain link system are labeled A and b.
, c, d. The bracket 7 is fixedly connected to a rotary table 8 rotating on rolls or the like, which rotary table 8 is supported on the immovable table via said rolls or the like and rotates 360 horizontally. can do. Weight compensation takes place by means of a pneumatic cylinder 9, which is pivotably connected to a hinge 10 of the bracket 7, the piston rod of which serves as a supporting lever 17 of the weight compensating system. It supports a regular four-bar chain link system.

When the arm 1 moves in and out, the bearing c (hinge point) and the hinge d remain spatially stationary. The piston rod of the compressed air cylinder 9 is connected to a four-bar chain link system A, b, c, d via a first connecting lever 15 and a second connecting lever 13 connected to a hinge 14 forming the apex of a triangle.
is connected to.

On the one hand, the second link lever 13 is connected by a link 14 to the piston rod of the pneumatic cylinder, and on the other hand, the first link 3 is pivotably supported in a bearing c. Histicle c' of short leg-shaped part 12
This leg-shaped portion 12 is connected to the first link 3.
A rigid structural part of the bearing part c towards the hinge d.
It is in an eccentric position relative to the The above-mentioned hinge 14 is connected via a first connecting lever 15 to a hinge d of a four-bar chain link system for additional support.

By the way, when this four-bar chain link system moves from the entered working position shown in FIG. 2 to the extended working position shown in FIG. 12, the tip of the pressurized air cylinder 9 is pivoted downwards, so that the support moment is adapted to changes in the load moment. The corresponding forces acting on the hinge 14 of the pneumatic cylinder 9 are shown in detail in FIGS. 3 and 4.

As can be seen from the figure, in the running state (Fig. 4), the force F9 of the cylinder is the resultant force of the force Fl5 or Fl3 generated from the first coupling lever 15 and the second coupling lever 13. exactly equal to the force in the cylinder. The relationship of forces will be explained below.

During the entry and exit of a four-bar chain link system with a load held by grippers, in the entry state (FIG. 2) due to the pivoting of the pressurized air cylinder 9 or the cylinder axis about the hinge 10, the The moment of the force acting on one coupling lever 15 with respect to the support c of the bracket 7 is smaller than in the running state (FIG. 1).

Both force components F i 5 in the run-in or run-out state (in this case 15a indicates the force component in the run-in state and 15e indicates the force component in the run-in state) are therefore applied to the lower short web link 6, which also produce counterclockwise moments of different magnitudes with respect to the bearing c of the bracket 7. The supporting force F4 regarding both hinge points of the longer second link 4 is
, giving rise to clockwise moments of different magnitudes. The arrangement and dimensions of the hinge c' of the leg 12 relative to the coupling levers 13 and 15 and the first link 3 are such that the load held by the gripper is held in a variable manner by the counterclockwise rotation and The above moments in the clockwise direction are selected so that they occur. This means that the force F9 produced by the pressurized air cylinder is constant. In general, when the force F4 shown in detail in FIGS. 1 and 2 is applied to the longer freely pivotable second link 4, the following force will be applied to the first coupling lever 15: The formula holds true.

As can be seen from Figures 1 and 2, the force F4 acting on the second link 4 is a force Fs (self-weight and load force) whose direction does not change, and a force Fb (the force of the hinge of the four-bar chain link system). b), the point of application of this force is the center of gravity 16 on arm 1 of the four-bar chain link system.

From the force Fl5 on the first coupling lever 15, obtained by the above formula, the force F9 and the force Fl3 are obtained by decomposition of the force, as shown in FIGS. 3 and 4.
The invention is not limited in principle to the illustrated embodiment.

The invention can be used whenever different forces act on the center of gravity of a four-bar chain link system depending on different working positions. The action of the coupling lever mechanism according to the invention between the white body of the four-bar link system and the weight compensation system, as already mentioned in the introduction, in particular reduces the required driving force for the pivoting of the four-bar link system. It can be reduced. In addition,
The weight compensation system in the actuating device illustrated in FIGS. 1 and 2 is designed, for example, in a double manner, also symmetrically with respect to the central plane, in order to ensure that the forces act symmetrically on the entire four-bar chain link system. can be placed.

[Brief explanation of the drawing]

Figure 1 is a schematic side view of the operating device in the running state;
The figure is a schematic side view of the operating device of FIG. 1 in the running state;
3 is a diagram showing the supporting force in the running state of FIG. 1, and FIG. 4 is a diagram showing the supporting force in the running state of FIG. 2. 1...Arm, 2...Gritzpa, 3...Link,
4... Link, 5... Connecting link, 6... Web link, a... Hinge, b... Hinge, c... Support part, c'... Link, d... Link , 7... Bracket, 8... Rotary table, 9... Pressure air cylinder, 10... Hinge, 12... Leg-shaped portion, 13...
...Connection lever, 14...Change, 15...Connection lever, 17...Support lever.

Claims (1)

Claims: 1. An operating device comprising an arm 1 with a gripper 2 or the like at its free end, which arm 1 connects first and second links 3, 4 and one connecting link 5. and a four-bar chain link system 3, 4, 5, 6 consisting of one web link 6
and is supported by a pivotable weight compensation system 9, in which case the arm 1 is provided with a four-bar chain link system 3,
One end of each of the first and second two links 3 and 4 of 4, 5, and 6 are connected via a hinge a and a hinge b, and the arm portion between the hinge a and hinge b is a four-bar chain link. The other end of the first link 3 is rotatably supported by a support c that is immovable with respect to the bracket 7 of the operating device, and the second link 4 The other end is connected via a hinge d to a web ring 6 that is rotatable about a support c that is immovable with respect to the bracket 7, and the web ring 6 is connected to a weight compensation system 9.
Weight compensation system 9
has a pivotably supported support lever 17;
Two connecting levers 1, a first and a second, are attached to the support lever 17.
3 and 15 are connected via one common hinge 14, and the other end of the first connecting lever 15 is connected to the web ring 6 to which the second link 4 is connected. is connected to the hinge d of and supports the second link 4, and the second connection lever 13 is connected to the hinge c' of the first link 3, The hinge c' is located away from the support c, which is immovable with respect to the bracket 7, toward the side of the hinge d connecting the web link 6 and the second link 4. An operating device having a weight compensation system, characterized by: 2. The first link 3 in which the hinge c', which is disposed away from the support c toward the hinge d of the web ring 6, is pivotably supported on the support c, which is immovable with respect to the bracket 7. The operating device according to claim 1, wherein the operating device is arranged on the short leg-like portions 12 of the operating device. 3 The second connection lever 15 supported by the first connection lever 15
3. The operating device according to claim 1, wherein the link 4 is on the gripper 2 side of the four-bar chain link system. 4. The operating device according to claim 1, wherein the support lever 17 is supported in a pivotably supported pressurized air cylinder 9.